1. Technical Field
The present invention relates to a projector.
2. Related Art
In the related art, there are known projectors each including an illumination device, a light modulation device that modulates light emitted from the illumination device and forms an image according to image information, and an optical projection device that expands and projects the image to a projection surface such as a screen (for example, see JP-A-2001-312003).
The projector disclosed in JP-A-2001-312003 includes a color separation optical device that separates a light flux emitted from a light source into pieces of respective color light of red, green, and blue, three liquid crystal panels that are installed for each of the pieces of separated color light, a prism that combines the color light modulated by the three liquid crystal panels, an optical projection device that projects the combined light, and a cooling device that sends air introduced from the outside of a casing to the liquid crystal panels to cool the liquid crystal panels. In the cooling device of the devices, cooling fans are installed according to the number of liquid crystal panels. The cooling fans independently send cooling airs to the corresponding liquid crystal panels.
Incidentally, high resolutions of projected images have recently been requested even in projectors. Accordingly, in order to cause the resolution of an image to be projected to be higher than the resolution of a light modulation device such as a liquid crystal panel, a light path changing element that changes a light path of the light is considered to be installed between the prism and the optical projection device and shift an axis of video light emitted from the light modulation device.
However, since the light path changing element is disposed between the prism and the optical projection device, the cooling device of the projector disclosed in JP-A-2001-312003 may not cool the light path changing element. An increase in the size of the projector and high luminance result in an increase in the size of the light path changing element, and thus a problem may arise in that the function of the light path changing element deteriorates due to heat generated in driving of the light path changing element.
Therefore, there is a request for a projector capable of supplying a cooling gas to a plurality of cooling targets such as the light modulation device and the light path changing element.
When a projector including a light path changing element is used in an event site such as an outdoor place, there is a concern of fats or dusts based on smoke being attached to the light path changing element. In this case, there is a problem that driving of the light path changing element is affected.
Therefore, there is a request for a projector in which dusts or the like are rarely attached to the light path changing element.